1. Field of the Invention
The present invention relates to a watertight electrical connector that ahieves an individual water-protecting function.
2. Description of the Related Art
The prior art watertight connector includes a rubber plug at a rear side of a terminal fitting to prevent the entrance of water into each cavity and a seal ring on engaging circumferential surfaces of male and female connector housings. However, the prior art connector may be used in an environment where the ends of wires drawn from the connector are exposed to water. In this situation, water may move along the wires due to a capillary action, and may enter the cavities to short-circuit adjacent terminal fittings. Thus, it is necessary to provide sealing between the respective cavities to provide a so-called individual water protection.
A prior art watertight connector with an individual water-protecting function is disclosed in Japanese Unexamined Patent Publication No. 9-134756. This connector is comprised of a female housing and a male housing. The male housing includes a receptacle into which the female housing may be fit. The front ends of cavities formed in the female housing are separated to define clearances between the cavities. The connector further includes a rubber seal that covers the front ends of all cavities and fills the clearances. Insertion portions project from the back surface of the receptacle for insertion into grooves formed in the front surfaces of the seal that are filled in the clearances.
The insertion of the female housing into the receptacle of the above-described male housing squeezes the outer peripheral portion of the seal between the cavities and the receptacle to provide sealing between the housings. Further, the insertion portions widen the grooves and press the portions of the seal that had been filled in the clearances around the individual cavities. Hence, sealing between the respective cavities is achieved.
The prior art watertight connector requires the seal to have a complicated shape. Furthermore, the front ends of the respective cavities of the female housing have to be formed in a separated manner, and the insertion portions need to project from the back surface of the receptacle in the male housing. As a result, the connector housings have complicated constructions. Further, the outer circumferential surface of the seal contacts substantially the entire inner circumferential surface of the receptacle of the male housing, and a contact resistance is created between the insertion portions and the grooves. Thus, a large a large frictional resistance exists during the connection of the housings, and a large force is needed to complete the connection. This leads to a problem of poor operability.
U.S. Pat. No. 4,875,870 discloses an article for protecting a connector that has a plurality of conductors. The article comprises a container, a base and a layer of gel, and is mountable on a side of a connector housing opposite the mating side. The layer of gel is arranged in the container, and is pierced by terminal fittings in cavities of the connector. The gel is compressed between the container and the base, and accordingly seals the terminal fittings at the back of the connector housing. However, the terminal fittings are inserted into the layer of gel in an intermediate portion thereof. Thus, the gel layer allows water to pass from one cavity to the neighboring cavity, and consequently the gel layer does not perform its sealing function well.
The present invention was developed in view of the above problems, and an object of invention is to provide an individual water-protecting function while reducing a connection force and without complicating the construction of housings.
The subject invention is directed to a watertight connector that has a housing with a plurality of cavities for accommodating a corresponding plurality of terminal fittings. The connector further includes at least one seal on a mating surface of the connector housing. Thus, the seal will be compressed between the mating surface and an opposed surface of a mating connector housing upon connection of the two connector housings with each other. Contrary to the gel layer of U.S. Pat. No. 4,875,870, the seal of the subject invention is on the mating side of the connector and not on a side opposite to the mating side. Accordingly, the sealing function of the connector housing is improved.
According to a preferred embodiment of the invention, the terminal fittings are pierced through the seal before the connector housing is connected with the mating connector housing.
The invention also is directed to a watertight connector comprising a first or female connector housing formed with a plurality of cavities that accommodate first or female terminal fittings. The connector further comprises a second or male connector housing with a receptacle into which the first connector housing can be fit. Second or male terminal fittings are accommodated in the second connector housing and project into the receptacle. The second terminal fittings can be connected with the respective first terminal fittings. At least one seal is compressed between a back surface of the receptacle and an opposed front surface of the first connector housing. The seal preferably is formed of a gelatinous material.
The invention also is directed to a watertight connector that has a female connector housing with a plurality of cavities that accommodate female terminal fittings. The connector further includes a male connector housing provided with a receptacle into which the female connector housing can be fit. Male terminal fittings are accommodated in the male connector housing and project into the receptacle. The male terminal fittings are configured to connect with the respective female terminal fittings when the female connector housing is inserted into the receptacle.
A gelatinous material is disposed between a back surface of the receptacle and an opposed front surface of the female connector housing. When the housings are connected, the seal or gelatinous material is compressed between the back surface of the receptacle and the front surface of the female connector housing to provide water protection between the housings and between the respective cavities.
The above described water protection can be realized merely by providing the gelatinous material between the back surface of the receptacle and the front surface of the female connector housing without complicating the construction of the connector housings. The subject invention enables a reduction of the required connection force because only a slight force is required to compress the gelatinous material at the final stage of connection of the connector housings.
A lever with a cam may be mounted pivotally on one of the connector housings and a follower that can be engaged with the cam may be provided on the other of the connector housings. Thus, the lever may be pivoted to assist in the connection of the connector housings. Since the gelatinous material is compressed using an operative force of the lever, the connector housings can be connected with a smaller force.
The seal or gelatinous material may be mounted on the back surface of the receptacle in advance while being penetrated by the second or male terminal fittings. Additionally, the second or male terminal fittings preferably are formed with hooks for hooking the seal or gelatinous material to prevent the seal or gelatinous material from coming out of the receptacle. Thus, the hooks are particularly useful when the gelatinous material is mounted on the back surface of the receptacle of the male connector housing in advance.
According to a further aspect of the invention, the seal can be compressed to between 30% and 70% of its longitudinal extension, and preferably to substantially 50% thereof.
The first connector housing may comprise an outer housing and an inner housing, and the inner housing may be arranged at least partly in a receptacle of the outer housing. The seal may be arranged between the front surface of the inner housing and the back surface of the receptacle of the second connector housing.
A second seal may be arranged in an accommodation space defined between a rear surface of the inner housing and a rear wall of the outer housing. The second seal preferably is made of a gelatinous material. Accordingly, sealing properties of the connector can be further improved.
Still further, preferably, the second seal is not compressed substantially, when the inner and outer housings are in a partial lock position. However, the seal is compressed between the rear surface of the inner housing and the rear wall of the outer housing when the inner and outer housings are in a full locked position. Additionally, the second seal preferably is penetrated by the first terminal fittings when the inner and outer housings in the partial lock position.
According to a further preferred embodiment, the seal individually seals the plurality of cavities with respect to each other upon being compressed between the first and second connector housings. Accordingly, the second terminal fittings are easily insertable into the second seal member.
These and other objects, features and advantages of the present invention will become apparent upon a reading of the following detailed description and accompanying drawings.